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llvm-project/llvm/test/Transforms/CorrelatedValuePropagation/and.ll

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[CVP] Remove a masking operation if range information implies it's a noop This is really a known bits style transformation, but known bits isn't context sensitive. The particular case which comes up happens to involve a range which allows range based reasoning to eliminate the mask pattern, so handle that case specifically in CVP. InstCombine likes to generate the mask-by-low-bits pattern when widening an arithmetic expression which includes a zext in the middle. Differential Revision: https://reviews.llvm.org/D68811 llvm-svn: 374506
2019-10-11 11:48:56 +08:00
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -correlated-propagation -S | FileCheck %s
define i32 @test(i32 %a) {
; CHECK-LABEL: @test(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[A:%.*]], 128
; CHECK-NEXT: br i1 [[CMP]], label [[CONTINUE:%.*]], label [[EXIT:%.*]]
; CHECK: continue:
; CHECK-NEXT: ret i32 [[A]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
;
entry:
%cmp = icmp ult i32 %a, 128
br i1 %cmp, label %continue, label %exit
continue:
%and = and i32 %a, 255
ret i32 %and
exit:
ret i32 -1
}
define i32 @test2(i32 %a) {
; CHECK-LABEL: @test2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[A:%.*]], 256
; CHECK-NEXT: br i1 [[CMP]], label [[CONTINUE:%.*]], label [[EXIT:%.*]]
; CHECK: continue:
; CHECK-NEXT: ret i32 [[A]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
;
entry:
%cmp = icmp ult i32 %a, 256
br i1 %cmp, label %continue, label %exit
continue:
%and = and i32 %a, 255
ret i32 %and
exit:
ret i32 -1
}
define i32 @test3(i32 %a) {
; CHECK-LABEL: @test3(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[A:%.*]], 256
; CHECK-NEXT: br i1 [[CMP]], label [[CONTINUE:%.*]], label [[EXIT:%.*]]
; CHECK: continue:
; CHECK-NEXT: ret i32 [[A]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
;
entry:
%cmp = icmp ult i32 %a, 256
br i1 %cmp, label %continue, label %exit
continue:
%and = and i32 %a, 1023
ret i32 %and
exit:
ret i32 -1
}
define i32 @neg1(i32 %a) {
; CHECK-LABEL: @neg1(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP:%.*]] = icmp ule i32 [[A:%.*]], 256
; CHECK-NEXT: br i1 [[CMP]], label [[CONTINUE:%.*]], label [[EXIT:%.*]]
; CHECK: continue:
; CHECK-NEXT: [[AND:%.*]] = and i32 [[A]], 255
; CHECK-NEXT: ret i32 [[AND]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
;
entry:
%cmp = icmp ule i32 %a, 256
br i1 %cmp, label %continue, label %exit
continue:
%and = and i32 %a, 255
ret i32 %and
exit:
ret i32 -1
}
define i32 @neg2(i32 %a) {
; CHECK-LABEL: @neg2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[A:%.*]], 513
; CHECK-NEXT: br i1 [[CMP]], label [[CONTINUE:%.*]], label [[EXIT:%.*]]
; CHECK: continue:
; CHECK-NEXT: [[AND:%.*]] = and i32 [[A]], 255
; CHECK-NEXT: ret i32 [[AND]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
;
entry:
%cmp = icmp ult i32 %a, 513
br i1 %cmp, label %continue, label %exit
continue:
%and = and i32 %a, 255
ret i32 %and
exit:
ret i32 -1
}
define i32 @neg3(i32 %a) {
; CHECK-LABEL: @neg3(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[A:%.*]], 256
; CHECK-NEXT: br i1 [[CMP]], label [[CONTINUE:%.*]], label [[EXIT:%.*]]
; CHECK: continue:
; CHECK-NEXT: [[AND:%.*]] = and i32 [[A]], 254
; CHECK-NEXT: ret i32 [[AND]]
; CHECK: exit:
; CHECK-NEXT: ret i32 -1
;
entry:
%cmp = icmp ult i32 %a, 256
br i1 %cmp, label %continue, label %exit
continue:
%and = and i32 %a, 254
ret i32 %and
exit:
ret i32 -1
}